Locking device for screws



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mi. 2U, wn I W. A. IBARKIER y LOCKING DEVICE SCREWS I Filed Jan. 27, 1921 lllatented l8r-ih, 2li, lhlild.

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llipplication led January 27, 1921.' `Serial No. 140,318.

`To LEZ/whom t may concern.' j j `Be it lrnown that l `lll/'nivonien A. Brinnnn a citizen olf the United States, residing' at la lllkhart, in the` county of Elkhart, State oi indiana, have invented certain new and uselul improvements in Locking; Devices lor `flcrews, oft which the following is a specilication. i

rlhis inventionrelates to `an improved device ifor'loclnng` screws against accidental turning, `and constitutes a continuation. in

`part oli-an application heretofore tiled by me on the 5th day of July 1919, Serial No. 808,888 for improvements in chucks, the same having eventuated in Letters .Patent lio.`1,389,731, dated September 8, 1921. rlhe `device ot the present invention has been designed more especially as a friction locking device it'or adjusting screws of chuclr jaws,

to prevent accidental turning or yielding of such screws under the pressure applied i to the jaws when the latter are clamped upon the work, or when the jaws are disengaged and the chuck running.

rlhe object of the invention is to provide a simpleineXpensive and reliable device in the `general nature ol a friction clamp `or grip to hold the screw against accidental turning, while permitting manual adjustment of thejaw by a wrench applied to the screw in the usual manner.`

My invention, itsmode ol' use, and the advantages inherent therein willbe readily apparent to persons skilled in the art as the invention becomes `better understood by reference to the following; detailed description,` taken in connection with the accompanying drawing in `which l have illustrated two practical. forms or embodiments of the principle oi2 the invention, and whereand 2;

rig. i is a. view similar to rig.` e, inustrating another form of screw grip or clamp embodying the principles of the invention; and v Fig. 5 is a detail `plan view `of the `grip vor clamp shown in Fig.` 4l.

upon y'the spindle (not shown) of' a lathe.

orlilr'e `machine in a `manner well understood. ln a` radially arranged groove "a" formed in the front lace o'l the chuck body is `mounted a gripping or work holding` aw, comprising` inner and outer jaw base menibers 8 and 9` which are adjustable lengthwise relatively to each other by meansof a jaw screw `l0, and a jaw proper 11, herein shownas of the reversible step jaw type secured to the outer jaw base member 9` by screws 12 and 13. rlhis construction ot' chuck jaw is old and well known in the art, except as to my improved friction grip or clamp for preventing accidental turning of the jaw screw 10. Y Referring now to those features of improvement in which the present invention chiefly resides, l designates the circular head ot the screw 10, which is formed with a circumferential` lf-shaped groove 14, yin which is sprung a friction split ring- 15 having radially proj ecting end portions 16 lying side by side and disposed within a socket 17 j pressures transmitted through the chuck jaw. rllhe laterally disposed ends 16 are disposed within the socket 17 and thereby loclr the friction ring against turning movement. rllhe rictional grip oi the ring on the jaw screw, however, does n ot interfere i with the adjustment or setting of the latter by a square tool entered in a correspondingly shaped socket 18 in the upper end of the screw, as is usual. i

Figs. 4 and 5 illustrate a Slightly different form of frictional grip or clamp, wherein the 'ring 15 is split on the opposite side from that shown in Figs. 1, 2, and 3 and is 'formed with an integral laterally offset loop or shank 16 which is engaged with the jaw socket 17 in the same manner and Jtor the same purpose as the arms 16. 1n this construction also, the ring member 15 before its application to the V-groove of the screw, is of slightly smaller internal diameter than that of the walls of the groove at the pointof engagement or' the latter by the ring, so that the latter hugs the groove with su'icient friction to effectively lock the screw against accidental turning.

The device of the invention holds the screw against accidental turning both when the jaws are engaged with the Work7 and also when the jaws are disengaged and the chuck ruiming, at which time the centrifugal jforce the jaws and the loosening combined have a. tendency to unscrew the jaws.

I claim:

l. ln a ehuelr.l the combination of a pair of rela-tively slidable jaw members, a Ajaw screw between said members lor effecting relative adjustment thereoi'7 an elastic ring non-rotatably held bv one of said jaw members and irictionally gripping said jaw screw.

2, ln a chuck7 the combination of a pair of relatively slidable jaw members, one of which is formed with a socket, a jaw Screw between said members for effecting relative adjustment thereof7 and an elastic split ring iirictionally gripping said screw and formed with an ol'sct portion confined in said socket.

3. In a clinch, the combination of a pair of relatively slidable jaw members, one oi which is formed with a socket, a. jaw screw between said members for effecting relative adjustment thereof, said jaw screw being formed with an annular V-shaped groove, and a split steel ring frictionally frriiping the walls oi" said groove and provide with a radial project-ion confined in said socket.

WENDELL A. BARKER. 

